Because of their high efficiency and long life, LEDs are expected to be used as the next generation of light-emitting elements in various light-emitting devices. Therefore, research and development for light-emitting devices using LEDs are being undertaken.
As a lighting apparatus having such a light-emitting device, a lighting apparatus having, in the body, a power block that converts a commercial power supply to DC output and four LED units (light-emitting devices) that have LEDs provided on a printed circuit board (e.g., see Non Patent Literature 1) is known.
In a lighting device recited in Non Patent Literature 1, a light-emitting device has a fan shape, and four light-emitting devices are combined into a circular shape. Each light-emitting device has four series circuits in which 12 LEDs are connected in series on or above a board, and the four series circuits are connected in parallel in each light-emitting device.